A 6-month study was conducted to evaluate the effect of three different methods for ascorbic acid (AA) supplementation on some productive and physiological performances of laying hens. Eighty (80), 4- month old Bovan pullets of similar body weight were divided into four experimental treatments (A, B, C, and D) of four replicates each in a completely randomized block design. Each replicate was subdivided into five hens. Control treatment A contained no AA in both basal diet and drinking water. Treatment B contained 1,000 mg AA / kg diet- basal diet and AA-free drinking water. Treatment C contained 500 mg AA/ kg diet - basal diet and 500 ppm AA- drinking water. Treatment D contained AA-free basal diet and 1,000 ppm AAdrinking water. Body weight gain, feed conversion ratio (FCR), body temperature, total and differential leucocyte counts and heterophils to lymphocytes ratio were investigated. Data were analyzed using analysis of variance (ANOVA) and Duncan's Multiple Range Test. Ascorbic acid supplementation had a significant (p< 0.05) positive effect on the body weight gain, body temperature and total leucocytes count compared to a significant (p< 0.05) negative effect on FCR. No significant treatment effect shown from supplementation of AA on heterophils to lymphocytes ratio. Ascorbic acid supplementation with feed could improve bird performances under optimum environmental or reduced body temperature.